Gardaí are appealing for witnesses after a collision on the Crumlin Road on Friday at around 4.40pm.
A car and motorbike collided and the motorcyclist, a man in his 30s, was taken St. James Hospital and is in a serious condition.
The driver of the car, a woman, was uninjured.
Gardaí are appealing for anyone who may have witnessed the collision or can assist them to contact Sundrive Road Garda Station at 01 6666608, the confidential line 1 800 666 111 or any Garda Station.
